PHP 8.3 support

[heddn]

• League\Glide\Manipulators\Watermark::setWatermarks(): Implicitly marking parameter $watermarks as nullable is deprecated, the explicit nullable type must be used instead
• League\Glide\Server::setResponseFactory(): Implicitly marking parameter $responseFactory as nullable is deprecated
• League\Glide\Responses\SymfonyResponseFactory::__construct(): Implicitly marking parameter $request as nullable is deprecated

These are just some of the errors I'm seeing in my logs.

[barryvdh]

The first 2 are for https://github.com/thephpleague/glide
The 3rd on I fixed here also; #21